1. Field of the Invention
The present invention relates to a method of assembling a cabinet, particularly the type of cabinet having at least one telescopic shelf.
2. Description of the Related Art
In certain types of cabinet with telescopic shelves, the guides for the telescopic shelves are fixed to the cabinet by brackets having a pair of vertically spaced lugs which diverge in a vertical direction. In this case, a respective bracket is provided at each end of the guide and each bracket is fixed in place by inserting one or other of the lugs into a mounting hole and then forcing the other lug so that it fits into a vertically spaced mounting hole, whereupon the two lugs hold the guide securely in place.
Such an arrangement is not suitable for use with electronic equipment, as when the shelves are extended telescopically from the cabinet, the bending moment on the rearmost brackets is considerably exaggerated, so that the vertical force acting on the rearmost bracket tends to cause this bracket to pop out of engagement with the mounting holes.
Therefore, for such applications, it is necessary to bolt each bracket in place to ensure that it remains engaged with the mounting post. Such an arrangement has a disadvantage that each bracket has several loose pieces which can easily be dropped inside the cabinet, and also in that the brackets are time consuming to install which is particularly a problem in installations which require numerous cabinets, each of which has numerous telescopic shelves.
U.S. Pat. No. 3,110,536 discloses a method of installing a telescopic shelf in a cabinet comprising an opening at one side and being substantially rectangular in plan, a pair of rear mounting posts extending vertically in the two corners of the cabinet remote from the open side, and a pair of front mounting posts extending vertically in the corners of the cabinet adjacent to the opening, mounting holes being provided in each pair of mounting posts, the method comprising the steps of installing a guide into the cabinet, the guide comprising a longitudinally extending channel portion for receiving a respective edge of the telescopic shelf, a first bracket fixed at the rear end of the guide and a second bracket fixed at the front end of the guide, the first bracket being provided with a first lug, the second bracket having a second lug; the steps of installing the guide comprising fitting the first lug in a mounting hole in a rear mounting post and moving the guide longitudinally until the first lug is secured in the mounting hole, and twisting the guide about a longitudinal extending axis, so as to insert the second lug into a mounting hole in the front mounting post, the engagement of the second bracket with the front mounting post preventing movement of the guide longitudinally sufficient to release the first bracket from the rear mounting post; installing a second guide in a similar manner so that its channel portion faces the channel portion of the first guide; and sliding the opposite edges of a telescopic shelf into the facing channels.
With this arrangement, when the shelf is extended and loaded vertically thereby transmitting an upward vertical load to the first bracket, the first bracket cannot be disengaged from the rear mounting post as to disengage the hook from the mounting hole requires movement of the guide longitudinally in the horizontal direction, which is prevented by the second bracket. As the brackets are fixed to the guide and, the fixing of the guides within the cabinet is carried out purely by engagement of parts of the brackets, with the mounting posts, there is never any need for loose pieces to be used within the cabinet.
In practice, it has been found that, with this arrangement, the telescopic shelves can be installed 95% quicker than with guides which must be bolted in place. This represents a enormous time saving for installations where numerous cabinets are used. It also allows unskilled operators to install shelves without tools, allowing an operator to adjust the position of the shelves without difficulty. Access for the installation is only required from the front, so that there is no need to remove the side panels of the cabinet.
There is a growing need within electronic cabinets to mount equipment of various xe2x80x9cmounting standardsxe2x80x9d and of various front to back (depth) dimensions. Some of this equipment requires that the front mounting posts and the rear mounting posts are set at depths which are specific to that equipment. In some cases, these centres will not match the fixing centres of side rails or telescopic slides. In such cases, extra pairs of vertical mounting posts are required to accommodate these various depth requirements. In densely populated cabinets, it is often impossible to fit these mounting posts.
According to the present invention, the method disclosed in U.S. Pat. No. 3,110,536 is characterised in that at least one of the brackets for each guide is telescopically adjusted to set the position of the guide relatively to at least one of the mounting posts in the depth and/or width directions of the cabinet.
This arrangement enables great versatility in mounting the shelf guides at appropriate positions in the cabinet to meet operational requirements. For example, short guides can be fitted in deep cabinets by using the brackets to bridge the difference in depth.
The range of application is therefore dramatically greater than fixed centre versions of this type of quick fit assembly, and is a unique, and cost effective solution, for populating a densely packed cabinet with equipment of widely varying depth or width measurements, whilst preserving the quick fit characteristics of the design.
For depth adjustment, at least one of the brackets may be telescopically adjustable relatively to the guide in the longitudinal direction of the guide. For width adjustment, both brackets will need to be adjustable and two parts of each bracket may be telescopically adjustable relatively to one another in the width direction of the cabinet.
The present invention also includes a cabinet comprising an opening at one side and being substantially rectangular in plan; a pair of rear mounting posts extending vertically in the two corners of the cabinet remote from the open side; a pair of front mounting posts extending vertically in the corners of the cabinet adjacent to the opening; mounting holes provided in each pair of mounting posts; a pair of guides being mounted at opposite sides of the cabinet and having facing channel portions between which the telescopic shelf is slidably received; each guide being attached within the cabinet by a first bracket fixed at the rear end of the guide and a second bracket fixed at the front end of the guide, the first bracket having a first lug mounted in a mounting hole such that it must be moved by a certain amount in the longitudinal direction of the guide to be disengaged from its mounting hole, the second bracket having a downwardly inclined second lug fitted in a mounting hole, and engaging with the lowermost edge of a mounting hole, the engagement of the second lug with its mounting hole being such as to prevent the movement of the first lug by the certain amount; and a telescopic shelf slidably supported between the facing channel portions; characterised in that at least one of the brackets for each guide is telescopically adjustable to set the position of the guide relatively to at least one of the mounting posts in the depth and/or width directions of the cabinet.
If the first lug is planar and extends rearwardly from the first bracket, the lug is engaged by movement of the guide in the direction in which the shelf is retracted. On the other hand, if the first lug is a hook, the open portion of which faces the front of the guide, the hook is engaged by being fitted into a mounting hole in a horizontal direction and pulled forwardly so that the bottom of the hook abuts against a vertically extending edge of the mounting hole. This second approach has been found to provide a more rigid support for the guide. Further, the hooks can be fitted into mounting holes which face across the cabinet, rather than mounting holes which face the front of the cabinet. This is advantageous with cabinets for electronic equipment in which the front facing mounting holes are conventionally used for mounting other equipment.
In order to provide a more rigid connection the first bracket preferably has two or more elevationally spaced first lugs. Although some vertical movement of the first bracket can be tolerated, another way of improving the rigidity of the brackets is for the height of the or each first lug to be substantially equal to the height of the mounting hole in which the or each first lug is fitted. This prevents movement of the first bracket in a vertical direction. Furthermore, a pair of vertically spaced second lugs may be provided and which diverge in the vertical direction, such that the uppermost lug engages with the top edge of a mounting hole. The width of the or each second lug is preferably substantially equal to the width of the mounting hole in which respective lug is engaged, to prevent movement of the second bracket in the direction in which the shelf is retracted and extended.
As the load on the second bracket is almost exclusively a downward vertical load, it is preferable for the uppermost lug to extend vertically by a greater extent than the lowermost lug to prevent the first bracket from being dislodged by a vertically downward load. When such a bracket is installed the longer uppermost lug is firstly inserted into a mounting hole and the guide is lifted slightly in order to force the second lug into its mounting hole.